Control device



Patented Oct. 9, 1945 *UNF-rizo-l sTA'rES "PATENT OFFICE *Y CONTRO/L,DEVICE Fred B. Aubert, Grosse Pointe, Mich.

This invention relates to new and useful improvements inelectriccircuits andmore particularly tosuch control by means' Vof gaseous fuelburners. l

. Although the electrical characteristics o f a flame haveheretoforebeen utilized in the control of. electric circuits,` it has been foundthat lwhen the burner control flame is created by gaseous fuel that'theAcontrolling operation is critical and thatthe circuit must be balancedor calibrated for different gaseous fuels.' It has been found that thisis due to the fact that in some instances the electron mass of the outerenvelope of a gaseous flame willl be definitely positive whereas withother gaseous flames the electron mass of the outerY envelope will bedefinitely negative. It vis therefore one object of this invention toprovide a control'which will not be affected by the electricalcharacteristics ofthe'fuel. l

Another object is to provide afcontrol which is particularly adapted foruse with the burner of a heating apparatus.

The invention consists in the improved construction and in thecombination of parts ofthe novel control tobe more fully describedhereinafterand novelty-of which Willbe particularly pointedjoutanddistinctly claimed.

In `theaccompanying Idrawing K to be taken as part of thisuspecicationthere are fully and clearly .inustmted several; preferred embodimentsrReferring to the drawing by. charactersdv of refg-fV erence, Idesignates generally a fluidfuel burner such as an-oil burner lhaving.an air tube or duct 2 and afuel, feed line; 3terminating in" afspra'ynozz1e 4 positionedpwithin the ductv 2.; A fan Vor blower 5 is connectedto the duct 2' to discharge l t air therethrough vto formacombustiblemixture with fuel, such as oil discharged from the nozzle 4 by the'pump-,6 whichis intercalated in the fuel line 32 The, fan 5 and pumpBaare'driven by an electric-motor 'I whichmay be provided with'an'electrically vor f `electrof-,magneticallyl operated svi/itchv control8.' AIn seriescircuit withfht-,ly electric Application Maren 7, 1942,serial 433,705

` 15 claims. (c a v actuator and switch contacts ofthe control 8 l.15s-L28) there is a relay switch 9 having an armature carried contact I0connected by a lead wire I I to the control 8. The fixed contact I I ofthe switch 9 is connected by a lead wire AI2 to the 'current supply line,wire I3, the other supply linewire I4 being connected to the freeterminal of the control 8. The primary I5 of a step down transformer I6is connected by a lead wire I1 to the lead wire I2 yand is connected bylead wire I8 to the supply wire 'I 4. The transformer secondary havingturns I9 and .20 supplies the relay coil 2| of switch 9 and also theelectricalnetwork of the electron tube 22 to be described hereinafter.

The igniting-rneans for the main burner I comprises a pair of pilotburners 23, 24 havingtheir single outlets directed so that the fuelstreams discharging therefrom impinge againstA each other. The burners23, 24 are further positioned adjacent the main burner I so that theflames of the impinging fuel streams are united to provide an ignitingflamel in the path of the combustible mixture discharged from the duct2V and nozzle 4. The pilot burners 23, 24 are fed with gaseous fuel frombranch supply pipes 25, 26 which may support the respective pilotburners and which are fed from a common supply pipe or conduit 21.The-burner 23 has. a supporting base 28 secured and sealed to the pipe26 and carrying a mixing tube formed by a tubular portion 29 of electricinsulating material and an electrical conducting cap ring element 30 ofmetal positioned at the Vburner tip. The tube portion'ZS is providedwith' electrical conductor and forming'the burner mixing tube. Air inlet34, of which there may be one or more are provided through the member 33so that there will be proper mixture of air with the fuel dischargedfrom the burner 24. Positioned adjacent the outlet of the burner 24there is an electrical sparking means 35 such as a spark plug f havingspark electrodes 36, 31 to provide a high tension spark for igniting thefuel supplied'by the burner 24. The plug 35 is supplied with hightension currentfrom an ignition transformer 38 f having one side of itssecondary 39 connected by a lead wire 40 to the electrode 36. Theotherelectrode 31 is connected by a lead Wire 4I to the armature carriedcontact 42 of a relay switch 43,

the fixed contact 44 of switch 43 being connected by a lead wire 45 tothe free terminal of the transn former secondary 39.

The relay coil 46 of switch 43 is in series circuit with the solenoidcoil 41 of an electrically operated fuel valve 48, one terminal of coil46 being connected to one terminal of coil 41 by a lead wire 49. Theother terminal of relay coil 46 is connected by a lead wire 59 to thexed contact I of a control switch 52 having a movable contact 53 andwhich may be a room thermostat or other automatic switch responsive tothe output of the main burner I. switch contact 53 is connected by alead wire 54 to lthe secondary 55 of a step down transformer 56 whichhas its primary 51 connected across the lead wires I3, I4. terminal ofthe transformer secondaryr55 a lead wire 51a connects to the freeterminal of the solenoid coil 41. transformer 38 is also connectedacross and fed from thelead wires I3, I4. l The `electron tube v22which, for example, may b'ezof the type known on the market as the No..iobiiiaciotron has the usual electrodes 59, tu, being respectively theanode and the cathode. Inte'i'posed between the tube electrodes there isa screen grid 6I vand a control element or grid S2. The usual filament`e3 isprovide-d for heatingr tbe cathode. A lead wire 64 connects fromone terminal o'f tlie filamentv 53 to one end of the transformersecondary 2 0, from the other end of which lead wire 65 `connects to theother side of the filament to complete its circuit. The cathode -B'isconnected by alead 'Wire as to theiead' wire 85; YFrom 'the anode, alead wire 61 connects to the relay coil 2lU and from the othercoil'terininal a -lead'wire 58 connects to the free eh'd of thetransformer secondary I9. From the burner tip conducting member 30 alead wire 69 extends vto the control grid' of the burner controllingelectrically operable 'switch 'means comprisingth'e ltube 22 and relay9. From the electri'ca'liy conductive burner tube a lead wire 'mconnects to ground. Connected between the leadvlire 1I of vthe screengrid 6I and the fila'- inentvlead wire 64 there isa `condenser 12 which,for may have a, 'Capacity of 200 mmf. Connected between the lead wiresII and 69,

there is a condenser la having a oapaeity which,

for aix-ambie, maybe 50 mmf..

'The oeeration of the heating apparatus of Figs. l and 2, assuming thatthe current supply to leadfwires I3, I4, 4the gaseous fuel supply to thevalve 48,a1d-the liquid fuel supply to the pump 5 l'f available, iS "sOl-IOWSZ When the Switch 52 is-closed,as by a cal-l fortemperatureincrease, theflay coi-l 49 and the solenoid coil 41 areeach'energizeol by `oornpletio'n o'f the following circuitgef-rom thetransformer secondary 55 through `l'e'ad wire 54, closed switch contacts53, 5I, lead wire '50, to one terminal of lcoil 46, from thev other coilterminal through lead wire 49 to 'one terminal the solenoid coil 41 andthence from the other terminal of coil 41 Via lead wire 513. back to thetransformer secondary 55.` The valve 48 is thus opened by the coil 41andthe relay switch 43 is cl'o'se'd at contacts 42,

4-4 to complete the Acircuit of the spark plug 35,

which circuit is as follows: From the ignition transfer-mersecondary 39through lead wire 45 and switch contacts'44, 42 to lead Wire 4I and oneelectrode 31 of the plug and thence across thel spark gap to the otherelectrode 35 and via lead wire '49 `to the other terminal of thetransformer secondary 39. The gaseous fuel supplied The movable From theother through the conduit 21 from the open valve 48 will mix with theair supplied to the burners 23 and 24 so that the fuel mixturedischarging from the burner 24 will be ignited by the spark at the airgap of electrodes 36, 31. The flame of burner 24 will immediately ignitethe fuel mixture discharging from burner 23. The substantially equalsize impinging flames from these burners will bridge the gap between theterminals of the wires 59 and 1U at their connections to these burnersand will therefore establish the circuit from the control grid 62 vialead wires 69 and IIBV to ground. Since the pilot burners are sup- Theprimary 58 of the ignition rplied with the same kind of fuel and providellames of substantially equal size, the impinging flames will .provide apath of Aconstant current flow or of the same resistance to current flowirrespective of the type or kind of gaseous fuel employed', becauseconnecting positive to positive ame envelopes or negative to negativeflame envelopes results in the llame Contact establislfiing lthe maximumresistance which can be had across the flame path. This flame completedcircuit willrender the control grid 62 more positive so that the tube 22will be energized and rendered capable of current flow to complete thecircuit through the relay coil 2| from the transformer secondary I.Energization of oeil 2| will vClose the switch `contacts IG, IIa tocomplete the circuit through the motor control means or switch B so thatair anu vfuel will be supplied by the fan 5 and pump 6 respectively toprovide a combustible fuel mixtureI to be ignited by the implng'ingburner flames discharging from the pilotbu'rners 23, t will be apparentthat should the flames issuing from the burners 23, 24 fail, or eitherof them, or should -the flames not imping'e each other, the control gridcircuit to ground will'be broken and the t'ube 22 thereby deeriergized,which will stop operation of the burner I by the opening of "switch 9and the deenergization of the burner controlling switch means.'

Referring, toFig. 3, the lead wires I2 and I8 from the line wires 'I8and I4, respectively, are connected to the prim-ary 15 of a step downtransformer 16 having a center-tapped secondary 11-. The end termi-nailsof 'the secondary 11 are co'r'mectedby lead ywires 18, 19 to the anodes8U,

8| of a full-wave rectifier tube 8'2 having a cathode 83. The-electricalntwork iS the'usual rectifier circuit having the cathode lead wire 84,which i'S grounded, Cnh'td by a rsistance 10a-d 85 to a lead wire 86from the center tap of the transon `each side of the choke coil 81 Thelead wire 86 "is connected 'at Aits free 'end as ateo to one of thelamination-sof a Rochelle salts warping crystal or control element'Bl.The other lamination ofthe crystal 9i is connected to the flame `leadwire 69 of- Fig. 1,'so'thfat the burner controlling electricallyoperable switch means comprising the crystal y9| may be' connected toground through the` impinging pilot flames. Upon subjectin'g the crystallamination connected to the lead wire 86 to a continuous unidirectionalpotential, effected by the full wave rectification, the crystal warps orbends to actuate a movable insulatedfswitch contact 92 into closingengagementA with a fixed switch contact 93 to ycomplete a high voltageelectric circuit from the line -wires I3, I4 to and through the motorcontrol switch 8," the contact T92 being connected bya lead wire 94 tothelead *.Wire 'l3lan'd1` the contact -93 being connected tothe controlswitch 8 by lead wire 95.V

*The .operation ofthe heating apparatus when provided withthelcircuitarrangement. of Fig. v3

will, it is believed, be apparent from the foregoing description of Fig.1 andof the circuit Yof Fig.13. However, it may be noted that theresistance load 85isfsuch that the tube 82 Will b'e maintained energizedat all times so that immediatelyupon impingement of the names from theburnersf23,` 2d, a circuit to ground is completed throughthe impingingflames so that a continuousunidirec'- tionalvoltage Willbe applied tothecrystal'Sl which' will warp andclose the relay contacts 92, 93, therebyplacingth'e-burner; I inoperation. v

1 It will be apparent that the burnerl I has v been shown asa liquidfuelburner solely for the -purv pose of illustration and that itmaylbeaugaseous fuel burner havingv an v electrically"operated or solenoidvalve positioned inthe burner'gvas lineY in lieu of the control .switch8 and motor 1.

yHaving thus described fthe invention, 'what is fclaimed and is 'desiredto be securedfby YLetters Patent ofthe United States is:

1. lA control devicecomprising a plurality of gaseous fuel burners soconstructed and arranged that a fuel stream discharging from one of saidburners impinges against alfuel stream discharging from another of said`burners, means to'produce flame sizes substantially equal to each otherat said burners and tosupply said burners VvWith `the same kind ofgaseous fuel, a control means, an electrical' conductor operable toconnect the flame of one of said burners to said control means, and anelectrical conductor to connect the flame of theother of said burners toground, the impingement of said flames closing thel circuitbe tween saidconductors thereby-to render rsaidY control means effective. 'Y o 2LAcontrol device comprising a plurality `-of gaseous fuel burners soconstructed and arranged that a fuel stream discharging from one Vvofsaid burners impinges against a fuel stream discharging from another ofsaid burners, meansto produce impingingrames of substantiallyequal sizeat said burners and to supply said burners with the same kindof gaseousfuel,a control means, one of ksaid Aburners having insulating means toelectrically insulate its flame "from ground;V an v electricalconductorv to' connect the insulated flame to-said control means, andan'electrical conductor to connectfthe flameof the other of said burnersto ground, the impingement of said iiames closing the circuit betweensaid conductors thereby to render `saidcontrol means effective. V3. Acontrol device comprising an electron tube Cil havng electrodes and acontrol element, va plurality of gaseousfuel burners so constructed andarranged that'a fuel stream'discharging from one of said burnersimpinges against a fuel stream discharging from another offsaid burners,means to produce impinging flames of substantially equal size at saidburners andfto supply said burners with the same kind of gaseous fuel,means operable to electrically connect the flame of one of said'burnersto said control element, means to electrically insulate the flame ofsaid last-named one of said burners from ground, andmeanstolelectrically connect the'fla'me of the othenof' said burners 'togroundtthe impingement of'saidiiames closing the circuit between saidconductors thereby to controlthe op eration-@risata tube-l- 1 -f 2.4.`Acontroldeviceicomrirising a Rochelle salts control element,meansztos'upply 'a unidirectional continuous Apotential to one side ofsai'd'felement, a pluralityofgaseous fuelburners so constructed andarranged that a fuel stream discharging fromV oneV of said burnersimpinges against av fuel stream discharging from another of` saidburners, means to produce impinging names .of substantially equal sizeat said burners andl tosupply said burners with the same kind of gaseousfuel, means operableY to electrically connect theflame of one of saidburners to the other side ofsaid control element, means to/electrica'llyinsulater the flame of said last-named one of saidburriers from ground,and means to electrically connect the ame of the other of said burnerstoground,

the impingement of said flames subjecting said` control element to saidcontinuous potential` thereby to actuate said control element.

5. A control device comprising anelectron tube having electrodes and acontrol element, a burner having atube portion of electric'insulating-ma-z'4 terial, an electrical conductor carried vby'saidtube` portionand positioned for conductingY relation with the burner ame, a burnerhaving agroundg ed tube portionof electric conducting material inconducting relationwith its burner name, said burners having a fueldischarge of one burner di-l rected against a fuel' discharge from theother burner, means electrically connecting saidacon-r ductor to saidcontrol kelement so that said elec-` tron tube will be'capable ofcurrentiiow bysim-` pingement of the burner amesyand means-to Supply the samekind of -gaseous fuelto 'eachofsaid burners vand .to providesubstantiallyequal flame sizes at both burners so that apathioflconstant current iiow Will be' established by the impinging flames.

6. A control device comprising aplurality'of gaseous fuel burners, oneof said burnerslbeing constructed and arranged to discharge algaseousifuel stream in impinging relation to a gaseous fuel stream dischargedfrom another of said :burners, means operable to electrically connectthe flame of one of said burners to ground, means to electricallyinsulate the flame of the Lother ofl said` burners from ground, meansvto produce flames of substantially the same size atg'said one and saidother burner, an electrical conductor adapted to be in electricconducting relationfto the ame of said last-named'other of saidburners,l an electron tube having a circuit controlled therebyand havinga control element electrically connected to said electrical conductor,and aconduit for supplying the same kindof gaseous fuel to each of saidburners so that thesubstantially equal sizevimpinging flames'willprovide a path of constant current ow irrespective'of the kind of fueland Will electrically connect said control element to ground, thereby torender said tube conducting. 7

7. A control device comprising Va plurality of gaseous fuel burners, oneof said burners being constructedand arranged to discharge'a gaseousfuel stream in impinging relation to a gaseous fuel stream dischargedfrom another of said burners, means operable to electrically `connectthe flame of one of said burners to groundfmeans to electricallyinsulate the flame of they other of said burners from ground,` means toproduce ames of substantially the same size at saidone and said otherburner, an electrical'conductorr connected to said electrical conductor,a conduitr for supplying the same Vkind of :gaseous fuel to each of saidburners, and electric sparking means for igniting the fuel dischargedfrom Ysaid last'- named one of said burners thereby toA ignite the fueldischarged from said last-name`dcther of said burners.

8. A burner control device comprising a main fuel burner, mea-nscontrolling the supph7 of fuel to said burner, a yplurality of gaseousfuel pilot burners at least one of which has fa fuel stream directed toignite the fuel discharged from said main burner, said pilot burnersbeing so con-r structed and arranged that a fuel stream dis'-Y chargingfrom one of said pilot burners impinges against a fuel streamdischarging from `another of said burners, means to supply said pilotburners with the same kind of gaseous fuel vand to produce flames ofsubstantially equal size `at said pilot burners, yelectrically operableswitch means controlling the operation of said .burner controilingmeans, means to ignite the fuel discharging from said pilot burners sothat there will be ime pinging flames, means to electrically connect theflame of one pilot burner to said switch means, electric insulatingmeans interposed between said connecting means of said last-named onepilot burner and ground, and means to electrically connect the name ofsaid other pilot burner to ground so that said switch means will beenergized by impingement of the pilot burner flames.

9. A burner control device comprising a main fuel burner, meanscontrolling the supply of fuel to said burner, a plurality of gaseousfuel lpilot burners at least one of which has a fuel stream directed toignite the fuel discharged from said main burner, said pilot burnersbeing so constructed and arranged that a fuel stream discharging fromone of said pilotburners impinges against a fuel stream dischargingfromanother of said burners, means to produce impinging flames ofsubstantially equal size at said burners and to supply said pilotburners with thesame kind of gaseous fuel, Aan electron tube having 4acircuit controlling said burner controlling means and having a controlelement, means to ignite the fuel discharged from one of said pilotburners thereby to ignite the fuel ydischarge-d from the other of saidpilot burners, means to' electrically connect the dame of saidlastenamed other pilot burner to said control element, electricinsulating means interposed between ysaid connecting means of saidlast-named other pilot .burner andv ground, and means to electricallyconnect the flameof said last-named one .pilot burner to ground so thatsaid electron tube will be capable of current flow by impingement of thepilot burner flames.

10. A burner control device comprising a main fuel burner, meanscontrolling the supply of fuel to said burner, a plurality of gaseousfuel pilot burners atleast one of which has a fuel stream directed toignite the fuel discharged from said main burner, said pilot burnersbeing 'so 'cone structed and arranged that a fuel stream dischargingfrom one of said pilot .burnersimpinges against a fuel streamdischarging fromnanother of said burners, means to produce .impingingflames of substantially equal size at said .burners and to supply saidpilot burners with the same y kind of gaseous fuel, an electric switchcontrolling the operation of said burner controlling means, a warpingcrystal yoperable to actuate said switch, means to supply aunidirectionalcontinuous lpotential to one side of said crystal, meansto ignite the fuel discharged from oneof said. pilot burners thereby toignite the fuel discharged from the other of said pilot burners,means toelectrically Vconnect the flame of said last-named other pilot burner tothe other side of said crystal, electric insulating means interposedbetween said connecting means 'of -said last-named other pilot burnerand ground, and means to electrically connect the `flame of saidlastenamed one pilot burner to ground so that said crystal will bewarped upon impingement of the pilot burner flames.

1l. A burner control device comprising a main fuel burner, a vpluralityof pilot burners operable to produce flames of substantially equal sizeand so related that their respective flames 'will impinge eachother,means 'to supply the same kind of gaseous fuel to said pilot burners, atleast one of said pilot burners being so related to said main burnerthat the flame `of said one pilot` burner can ignite the fuel suppliedto said main burn-- er, an electron tube having a 'control grid with acontrolling circuit, means forming a series gap in said grid circuit and.positioned to be .bridged by the impinging pilot burner flames, andmeans controlling the initial supply offuel to said main burner andcontrolled by said tube, said tube being rendered effective uponcompletion of said grid circuit by the impinging pilot flames.

12. A burner control device comprising a main fuel burner, a pluralityof pilot burners so related that their respective flames will impingeeach other, at least one of said pilot burners being so related to saidmain burner that the flame of said one pilot burner can ignite the fuelsupplied to said main burner, warpable means having a circuitcontrolling its operation, said circuit having spaced terminalsproviding a gap to be bridged by the impinging pilot burner flames, andmeans controlling the initial supply` 'of fuel to said main burner andcontrolled by said warpable means, said controlling means being renderedeffective upon completion of said circuit by the impinging pilot flames.

y13. A burner control device comprising a main fuel burner, electricallyoperable fuel supply means for said burner and having a circuit, anormally open switch controlling said circuit, electrically energizedmeans operable to close sai-d switch, a pair of pilot burners sopositioned that their respective flames will impinge each other, atleast one of said pilot burners directing its flame to ignite said mainburner, means to produce substantially equal flame sizes at said pilotburners, means to supply thesame kind of gaseous fuel to each of saidpilot burners, said electrically energized means having a controlling.circuit, said pilot burners being positioned in series in saidcontrolling circuit and being spaced to provide a series gap in saidcontrolling circuit, and means to .ignite the fuel supplied to saidpilot burners to provide impinging flames bridging said gap thereby tocomplete said controlling circuit for closure of said normally openswitch.

14. A burner control device comprising a main fuel burner, electricallyoperable fuel supply meansfor said burner and having a circuit, anormally open switch controlling said circuit, electronic meansoper-able to close said switch, a pair of pilot burners so positionedthat their respective flames will impinge each other, at least one ofsaid pilot burners directing its flame to ignite said main burner, meansto produce lsubstantially equal flame sizes at said pilotburners, meansto supply the same kind of 'gaseous fuel to each of said pilot burners,said electronic means having a `grid controlling circuit, said pilotburners being positioned in series in said grid controlling circuit andbeing spaced to provide a series gap in said controlling circuit, andmeans to ignite the fuel supplied to said pilot burners to provideimpinging flames bridging said gap thereby to complete said controllingcircuit for closure of said normally open switch.

15. A fluid fuel burner safety starting means comprising a pair of pilotburners directed relative 'to each other for flame impingement andelectrically insulated from each other to provide a circuit gap, meansto supply the same kind of that the impinging llames will complete saidcon-v trolling circuit thereby to render operation of said electricallycontrolled switch closing means dependent upon impingement of said pilotburner flames.

FRED B. AUBERT.

